Life Science chapter 4 Flashcards
What is a cell?
Basic structural, functional unit of all living things.
Smallest unit of life and the buildings blocks for all living things.
100 trillion cells in average human.
Organelles: metabolism, production, transportation, secretion of substances.
Root hair cell?
Absorption of water and mineral ions
It has a long extension that increases the surface area for absorption.
Palisade cell?
Main site of photosynthesis
Many chloroplasts to capture as much as possible light.
Xylem cells:
Water and minerals transport transport from root to leaf.
Dead, hollow, no end walls - no obstruction to flow of water and m ions.
Red blood cells?
Oxygen to all body cells
Lack nucleus and organelles, contain hemoglobin to carry oxygen.
Sperm cell?
Fertilize egg in fertilization
Special tail to help swim to egg cell.
Motor nerve cell?
Transmit electrical impulses to effectors like muscles.
It has a very long axon, insulated by a myelin sheath to prevent leakages of impulses.
What is a tissue?
A group of cells working together to perform a particular task.
Ciliated epithelial tissue?
In trachea and bronchus, have cilia: make flicking movements to sweep out dust, bacteria and mucus to outside.
Human cheek epithelial cell?
Lines inside mouth, many cells packed together.
Secretes a continuous supply of mucus to maintain a moist environment in mouth.
Nervous?
Main component of nervous system.
Composed of many long neurons/nerve cells: receive and transmit impulses very fast between the body and nervous system.
Muscle tissue?
Soft tissues compose muscles - made of long muscle fibre cells that are made of contractile proteins, gives rise to muscles’ ability to contract.
Why is the heart vital?
Circulatory: pumps blood through blood vessels to body
Why is the brain vital?
Nervous system: controls the coordinating of information received from the sense organs.
Why are the lungs vital?
Respiratory: breathe oxygen in so it can go into the blood stream, and CO2 removed from the body when exhale.
